US president Barack Obama reflects on the brutal killing of journalist Steven Sotloff at the hands of Isis, saying his life stood in sharp contrast to those of his killers. ‘They make the absurd claim that they kill in the name of religion … [but Steven] … deeply loved the Islamic world,’ Obama says. The president condemns the killing and says it will only stiffen America’s resolve in Iraq

We’re going to wrap up our live coverage for the day. Here’s a summary of where things stand:

US President Barack Obama said the US would “degrade and destroy” Isis forces in Iraq. He prepared to meet Thursday with European leaders to discuss specifics. Britain, France and others have signalled their willingness to join in a military campaign.

The campaign could include air strikes inside Syria, US defense secretary Chuck Hagel indicated Wednesday, saying the Pentagon had prepared “a number of options.”

Air strikes alone would not defeat Isis but the US will not put “boots on the ground” for combat operations, Hagel said. He said Baghdad needs a more inclusive government.

Read our analysis of possible military options on the tablehere. Read our analysis of which countries may participate here.

The mobilization followed the release Tuesday of a video showing the killing of US journalist Steven Sotloff by Isis militants, two weeks after a similar video of the murder of US journalist James Foley.

“We will not allow our enemy to hold us hostage with the sole weapon they possess: fear,” said a Sotloff family representative. The mother of James Foley said in a statement that her family was “heartbroken” for the Sotloffs.

In the Sotloff video, Isis militants threatened the life of a British captive, identified as a 44-year-old aid worker.

A Free Syrian Army leader complained that the United States does not maintain contact with the opposition leadership, even as the CIA provides military aid to dozens of individual commanders and smaller groups.

Sotloff family: 'he sacrificed his life to bring their story'

A representative of the Steven Sotloff family, Barak Barfi, has made a statement on CNN commemorating the slain US journalist.

Barfi says Sotloff was immersed in the lives of the people whose story he sought to tell. “Their story was Steve’s story,” Barfi says. “He ultimately sacrificed his life to bring their story to the world.”

Steve was no hero. He was one of us--he always sought to help... he indulged in South Park but was just as serious about filing a 3am story. ...

Despite his busy schedule, he always found time to Skype his father to discuss his latest golf game...

Steve had a gentle soul that the world will live without, but his spirit will live on in our hearts...

We will not allow our enemy to hold us hostage with the sole weapon they possess: fear.

Our hearts go out to the family of Jim Foley.

We ask the media to respect our wish for privacy.

Then Barfi switches to Arabic and addresses the leader of Isis directly, saying, ‘ya Abu Bakr,’ that he is “ready”, he does not have a knife in his hand.

Human Rights Watch is the latest group to report on a massacre of hundreds of soldiers by Isis in Iraq this summer:

Evidence indicates that militants from the Islamic State (IS) jihadist group executed more than 500 captives in Iraq earlier this year, Human Rights Watch said on Wednesday.

Around 1,700 soldiers surrendered to IS in June after its fighters seized second city Mosul and swept south towards Baghdad.

IS subsequently released photographs of dozens of men in civilian clothes apparently being executed by firing squad in desert areas, and said it had killed hundreds in total.

“Information from a survivor and analysis of videos and satellite imagery has confirmed the existence of three more mass execution sites, bringing the total to five, and the number of dead to between 560 and 770 men, all or most of them apparently captured Iraqi army soldiers,” HRW said.

Amnesty International on Tuesday reported that Isis had “launched a systematic campaign of ethnic cleansing in northern Iraq, carrying out war crimes, including mass summary killings and abductions, against ethnic and religious minorities”:

A new briefing, Ethnic cleansing on historic scale: the Islamic State’s systematic targeting of minorities in northern Iraq, published today presents a series of hair-raising accounts from survivors of massacres who describe how dozens of men and boys in the Sinjar region of northern Iraq were rounded up by Islamic State fighters, bundled into pick-up trucks and taken to village outskirts to be massacred in groups or shot individually. Hundreds, possibly thousands, of women and children, along with scores of men, from the Yezidi minority have also been abducted since the Islamic State took control of the area.

“The massacres and abductions being carried out by the Islamic State provide harrowing new evidence that a wave of ethnic cleansing against minorities is sweeping across northern Iraq,” said Donatella Rovera, Amnesty International’s Senior Crisis Response Adviser currently in northern in Iraq.

Diane Foley: 'We are just heartbroken for them'

The mother of slain U.S. journalist James Foley says she hopes the killing of a second American in Syria will galvanize world leaders to find peaceful solutions to global conflicts, the Associated Press reports:

Diane Foley, of Rochester, New Hampshire, told New England Cable News on Wednesday that she had hoped Steven Sotloff and other captives held by the Islamic State group in Syria would be spared. A video posted Tuesday showed a member of the militant group beheading Sotloff. A video released two weeks ago showed James Foley being killed the same way.

Diane Foley said she sends her deepest condolences to the Sotloff family and says “we are just heartbroken for them.”

She says she hopes the worldwide outrage over the killings is “funneled into goodness and peace.”

The US and Iraq have signed a deal to prevent, detect and respond to nuclear smuggling incidents, according to a state department statement:

On September 2, the Governments of the United States and Iraq strengthened their bilateral partnership to prevent nuclear terrorism by concluding an agreement to advance protection against nuclear and radiological smuggling. This “Joint Action Plan Between the Government of the Republic of Iraq and the Government of the United States of America on Combating Nuclear and Radioactive Materials Smuggling”, negotiated by the Department of State’s Bureau for International Security and Nonproliferation (ISN) and signed by Michael Koplovsky, Minister Counselor of Economic Affairs at U.S. Embassy Baghdad, and Dr. Mohammed Al-Janabi, Chairman of the Iraqi Radioactive Sources Regulatory Authority, expresses the intention of the two governments to work together to enhance Iraq’s capabilities to prevent, detect, and respond to nuclear smuggling incidents.

Checking in on the competition: al Qaeda leader Ayman al Zawahri on Wednesday announced the formation of an Indian branch of his militant group he said would “raise the flag of jihad” across the subcontinent, Reuters reports:

In a 55-minute video posted online, Zawahri also renewed a longstanding vow of loyalty to Afghan Taliban leader Mullah Omar, in an apparent snub to the Islamic State armed group challenging al Qaeda for leadership of transnational Islamist militancy.

Zawahri described the formation of “Al Qaeda in the Indian Subcontinent” as a glad tidings for Muslims “in Burma, Bangladesh, Assam, Gujurat, Ahmedabad, and Kashmir” and that the new wing would rescue Muslims there from injustice and oppression.

US Ambassador Samantha Power says the United States is hoping for unanimous approval of a UN resolution calling for global action to prevent the growing “phenomenon” of foreigners traveling to fight for terrorist groups when President Barack Obama hosts a Security Council summit on Sept. 25, the Associated Press reports:

Power told reporters Wednesday that foreign fighters like those in Iraq and Syria are participating in “brutal atrocities” in the countries they travel to, and often return home radicalized by their experiences “posing threats of the most profound kind to their fellow citizens.”

She said the resolution the US is drafting is aimed at strengthening the ability of governments to curb the flow of their citizens to war zones through improved information and intelligence sharing among other things.

US intelligence officials have concluded that Isis does not currently pose a direct threat of a major attack on an American city and that the group, despite its dramatic rise to prominence in the Middle East, is not comparable to “Al Qaeda pre-911”, writes Guardian Washington correspondent Paul Lewis, reporting further on remarks Wednesday by counterterrorism director Matt Olsen:

Details of the current US intelligence community’s assessment of Isis were made public on Wednesday in rare public remarks by Matthew Olsen, the departing director of the National Counterterrorism Center. [...]

Olsen conceded the militant group had made dramatic territorial gains in Syria and Iraq, and displayed an unprecedented skill at using the internet for propaganda.

He said it viewed itself as “the new leader in the global jihadist movement” although US intelligence officials maintain Al Qaeda currently is a more serious adversary.

But Olsen played down the risk of a spectacular Al-Qaeda-style attack in a major US or even European city, adding: “there is no credible information that [Isis] is planning to attack the United States”. He said there was “no indication at this point of a cell of foreign fighters operating in the United States - full stop”.

As our live blog coverage continues, here’s a summary of where things stand:

The US intends to destroy Isis and not merely contain it, US defense secretary Chuck Hagel said Wednesday. Air strikes in Syria are among the military options the Pentagon is proposing to the president, he suggested.

US president Obama arrived in Wales in advance of Nato summit meetings with European leaders Thursday. Obama was to seek participation in and support for a new effort against Isis.

A coalition to confront Isis is likely to include Nato plus Australia, as well as Turkey and perhaps Jordan, writes Guardian Middle East editor Ian Black. Also: Iran.

A plan to fight Isis began to crystallize after a video was released Tuesday showing the murder by the group of US journalist Steven Sotloff, the second American journalist killed by Isis in as many weeks.

The director of the US National Counterterrorism Center said Isis poses “a direct and significant threat... potentially to us here at home.”